TheDice951

i was driving home from work yesterday, i was doing some "spirited" driving on the back roads going to my house. i got on it about 3/4 throttle and at about 5000rpm it felt like something "gave out" and it sounded like a boost cut or something. I'm running spring only on my tial waste gate (12lbs) and that's all that read on the gate as well. now, even at idle, the exhaust sounds lower and "popier"

i checked for boost leaks, i have none. i check spark plugs, they are all good. i checked compression and got 125 x 4. i looked at the turbo as well and it seems OK, and i don't see any obvious signs of pre-turbo exhaust leaks either. it just sounds and feels funny, sluggish somewhat and barley any power in boost.

any other suggestions would be awesome, thanks

Paulyy

Do you have aftermarket chips to allow you to run 12 psi?

TheDice951

Yes, sorry, I have a gt30r with vettesse software. It was all installed by the precious owner, he had it set higher when I bought it with a boost controller. I replaced the mechanical boost controller with an HKS electronic one and have it turned off... So it runs off the spring only

Paulyy

ahhh, now it's a different story. best chance is either call up vitesse, and speak to john, since your running his software.

toddk911

I know you checked, but still sounds like a leak somewhere.

If you hear something different that would lead me to think exhaust/headers leak.

hp18racer

Under the heat shields they can be hard to find. Crack at the junction of the 2/3 header or the flanges on the crossover pipe where it bolts to the headers are places I have had fail more than once.

TheDice951

this weekend i will be pulling off the entire exhaust including the manifolds... i will be welding up all cracks and putting new gaskets/rings. thats all i can think it could be....

thanks guys

TheDice951

OK, so i checked:

spark plugs
wires
distributer cap & rotor
exhaust to turbo
boost pipes(couplers and all)
timing
compression
vacuum lines

all is good

it still runs like *** in boost and idles a bit rough. example: I'm driving down the road, I'm cruising at 3000 rpm in 3rd, i get on it a bit(not flooring it). the turbo seems to spool fine and boost starts to come on. it feels like the car gets slower for a second and then pulls like its suppose to. it hits about 9lbs and then the exhaust tone gets deeper and the car feels like i hit a wall? it is "popping" a lot on down shifts just sounds different all together.... i am stumped

on a, hopefully, different note. when i was checking the wires, making sure i was getting spark, the turbo water pump would start smoking when the car was shut off???

i am fairly good at figuring this kind of stuff out and this is just killing me.... all the help i can get is greatly appreciated

Dougs951

ok you probably ripped a coupler.

It *sometimes will only manifest itself under boost. I had a similar problem and that was the cause.

Check the undersides of the couplers.

black944 turbo

Do you have a boost leak tester? If not get one or make one. You can cut a fuel filter in half and boost leak test up to 5 psi. I am with Doug, you probably have a boost leak.

piperporsche180944

My brand new dual port wastegate got stuck open the first time I took the car out and boosted it. That could be it maybe, then again you would definitely know if this was the issue since the car would be pretty darn loud.

TheDice951

I took all the couplers off and looked them all over, I didn't see anything but who knows.....

I may check the wastegate because it does sound a bit louder....

TheDice951

anyone know why my turbo water pump would start sizzling and smoking when i turn the engine off?

Paulyy

are you sure the smoke isn't steam? mine did that. left a puddle on the floor.

the bearing on the motor shaft was gone so i replaced the whole thing.

TheDice951

Ok so I checked:

Pre turbo exhaust
Turbo
Boost pipes

The turbo spools fine, boosts to 12 lbs as long as I get into it slow. If I press the gas too fast it stops accelerating and starts popping.

Checked compression
Spark
Spark plugs
Distributor and rotor
Wires
Timing

All were fine and worked as should

Checked O2 sensor
MAF

Both work and are clean

Checked for vacuum leaks as well... None

Fuel pressure is also good as far as I can tell

I am thinking of checking the fuel pump, fuel filter and TPS

Any other ideas??
Please I need some other ideas!!